Honestly, this type of situation is quite shitty. What you can
do is to allow yourself to open up a gap bewteen the motorcycle
then when the opportunity presents itself on the right, accelerate
and change lanes. Just don't care about the car behind. What can
you do about it? There's a road hogger in front of you, not as if
it is your fault.
The main problem I can see for you is that whenever an
opportunity presents itself on the rght, it is likely the car
behind you that will filter into that lane before you. This will
result in you being unable to filter as your right blind spot will
be occupied. If so, then LPPL, better to be late for your
appointment than to cause any bodily harm to another road
user...
When I'm not in a hurry:
Slow down, wait for the right lane to clear, signal my
intention, change lane and over take.
When I'm in a hurry:
Switch on high beam, if traffic on the right is building up /
congested, signal my intention, wind down the window, send a hand
gesture, slowly inch towards the right until I'm completely in the
lane, overtake.
Whatever it is, allow all taxi drivers on the right to pass
first. And mutter prayer of thanks because my right hand is still
valid.